1. Technical Field
The present disclosure relates to an organic light emitting diode (OLED) display device, and more particularly, to a transparent OLED display device.
2. Related Art
An image display device has been developed to be thinner and have improved mobility and high performance. A liquid crystal display (LCD) device has largely replaced the cathode-ray-tube (CRT). Recently, an OLED display device having advantages in characteristics, e.g., color reproduction, thickness, power consumption, viewing angle, response time, and so on, than the LCD device is widely developed as a next-generation flat panel display device. The OLED display device is a self-emitting type device using an emitting layer of an organic material between electrodes. As a result, the OLED display device can be thinner than the LED device.
Recently, a transparent display device has been introduced and developed. With the transparent display device, both of an image screen and a background image are visible. Alternatively, the transparent display device is used as a window or as an image screen in a display driving time. The OLED display device is a suitable device for the transparent display device.
FIG. 1 is a schematic view of one pixel of the related art transparent OLED display device.
Referring to FIG. 1, one pixel PX of the related art transparent OLED includes a plurality of sub-pixels SPX1, SPX2 and SPX3 arranged in a vertical direction. An emission part EA of the first sub-pixel SPX1 is spaced apart from the emission part EA of the second sub-pixel SPX2 by a first distance D1. In addition, the emission part EA of the third sub-pixel SPX3 is spaced apart from the emission part EA of the second sub-pixel SPX2 by the same distance, i.e., the first distance D1.
The emission parts EA in the first to third sub-pixels SPX1, SPX2 and SPX3 should be spaced apart from each other by the first distance D1 to prevent a color mixture problem in adjacent sub-pixels.
In a white light emitting type OLED (i.e., a WRGB type), using a color filter as a color generating element, the first distance D1 can be controlled based on an emitting area, a distance between an emitting material layer (EML) and the color filter, or a width of a black matrix between the color filters. In a pixel independently emitting type OLED (i.e., an RGB type), the first distance D1 can be controlled based on the emitting area, a width of a bank B defining the emitting area, or a distance from the emitting material layer (EML) to a final image displaying surface.
The sub-pixels SPX1 to SPX3 have a vertical dimension greater than a horizontal dimension. The emission parts EA within each sub-pixel also has a vertical dimension greater than a horizontal dimension.